Liquid Dosage Forms - Solutions Flashcards
exam 1
1
Q
what are the three liquid dosage forms?
A
- solutions
- emulsion
- suspension
2
Q
what is a solution?
A
- homogeneous molecular dispersion
- drug molecules are completely dissolved
3
Q
what is an emulsion?
A
- oil in water or water in oil
- see particles suspended, usually liquid droplets
4
Q
what is a suspension?
A
- solid in water or oil
- see particles suspended, usually solid particles
5
Q
what are some examples of solution dosage forms?
A
- anything that is completely dissolved
- injectables, nasal solutions, ophthalmic solutions, otic solutions, irrigation solutions, enemas, douches, gargles, mouthwashes, juices
6
Q
what are the three advantages of solution dosage forms?
A
- homogenous - no problems of content uniformity
- easy to manufacture
- good bioavailability - body doesn’t need to do extra work because the drug is already dissolved in solution
6
Q
what are the components of a solution (7)?
A
- active ingredient
- solvent
- buffering agent
- preservative
- antioxidant, chelating agent
- flavor and sweetener
7
Q
what are examples of solvents?
A
- water, vegetable oils (for long-acting)
- co-solvent (ethanol, glycerin, propylene glycol)
8
Q
what are the solvents used for?
A
to increase the solubility of a drug in solution
9
Q
what are buffering agents?
A
- maintain the solution pH
10
Q
what are preservatives?
A
antimicrobial agent - keeps microbes out
11
Q
what is a chelating agent/antioxidant?
A
prevents unwanted chemical reactions
12
Q
what are two examples of a flavor/sweetener used in solutions?
A
sucrose and sorbitol
13
Q
what is the buffer principle?
A
- a solution of a weak acid and a salt of its conjugate base
- maintain the pH of a solution
14
Q
what does a weak acid remove?
A
- added base (OH-)
- HA + OH- <—-> H2O + A-
15
Q
what does a salt (conjugate base) remove?
A
- removes added acid (H+)
- A- + H3O+ <—-> HA + H2O
16
Q
A
